原标題：工(gōng)學(xué)院課題組液晶與高分(fēn)子複合材料多(duō)層微結構的構建與光調控研究進展

Original Title: Progress in the Construction and Light Regulation of Multilayer Microstructures of Liquid Crystal and Polymer Composites in the Research Group of the College of Engineering

　　液晶與高分(fēn)子複合材料的多(duō)層微相結構在納米模闆、納米打印、信息防僞等領域具(jù)有(yǒu)潛在的應用(yòng)前景。近年來，它受到了研究人員的廣泛關注。由于液晶單元具(jù)有(yǒu)“刺激響應”特性，将液晶作(zuò)為(wèi)官能(néng)團引入嵌段共聚物(wù)中(zhōng)，可(kě)以制備和控制大面積的規則納米結構。然而，液晶與高分(fēn)子複合材料的多(duō)層微納結構的研究仍面臨一些困難：首先，随着納米技(jì )術的發展，納米科(kē)學(xué)對于更複雜、更精(jīng)細的納米器件更加迫切。多(duō)層次納米結構的構建也成為(wèi)高分(fēn)子複合材料領域的研究難點和研究熱點。其次，在室溫下實現上述複雜納米結構的快速、可(kě)逆和準确調控仍然具(jù)有(yǒu)挑戰性。近日，北京大學(xué)工(gōng)程學(xué)院于海峰課題組針對上述兩個問題提出了相應的解決方案。

The multi-layer micro-phase structure of liquid crystal and polymer composites has potential application prospects in the fields of nano-template, nano-printing and information anti-counterfeiting. In recent years, it has received extensive attention from researchers. Since liquid crystal cells have "stimulus response" characteristics, the introduction of liquid crystals as functional groups into the block copolymers makes it possible to prepare and control large-area regular nanostructures. However, the research on multi-layer micro-nanostructures of liquid crystal and polymer composites still faces some difficulties: First, with the development of nanotechnology, nano-science is more urgent for the more complex and finer nano-devices. The construction of hierarchical nanostructures has also become a research difficulty and research hotspot in the field of polymer composites. Second, it is still challenging to achieve rapid, reversible and accurate regulation of the above complex nanostructures at room temperature. Recently, Yu Haifeng's research group of the School of Engineering of Peking University proposed corresponding solutions to the above two problems.

　　本課題組在前人工(gōng)作(zuò)的基礎上，将脲鍵引入到含有(yǒu)偶氮苯液晶盒的液晶嵌段共聚物(wù)中(zhōng)。在微相分(fēn)離過程中(zhōng)，脲鍵與液晶嵌段共聚物(wù)的分(fēn)散相和連續相均形成氫鍵。嵌段共聚物(wù)中(zhōng)的超分(fēn)子鍵與嵌段的相互作(zuò)用(yòng)影響了分(fēn)散相各組分(fēn)在退火過程中(zhōng)從各向同性溫度到室溫的結晶過程，從而獲得了一個非A域，其中(zhōng)一個結晶區(qū)和一個晶體(tǐ)區(qū)域并存。在沒有(yǒu)任何摻雜的情況下，研究團隊僅使用(yòng)液晶的氫鍵和聚合物(wù)本身就實現了尺寸小(xiǎo)于10 nm的分(fēn)級納米結構的構建（圖1）。這部分(fēn)工(gōng)作(zuò)發表在 Macromolecular Rapid Communications 上。

On the basis of previous work, this group introduced a urea bond into a liquid crystal block copolymer containing an azobenzene liquid crystal cell. During the microphase separation, the urea bond forms a hydrogen bond with both the dispersed phase and the continuous phase of the liquid crystal block copolymer. The interaction between the supramolecular bond and the block in the block copolymer affects the crystallization process of the components of the dispersed phase from the isotropic temperature to the room temperature during the annealing process, thereby obtaining a non- A domain in which a crystal region and a crystal region coexist. In the absence of any doping, the research team realized the construction of hierarchical nanostructures with a size below 10 nm using only the hydrogen bonding of liquid crystals and the polymer itself (Fig. 1). This part of the work was published on Macromolecular Rapid Communications.